Steam jet drum washing machine

ABSTRACT

Disclosed herein is a drum washing machine which is capable of lifting clothes to a predetermined height and then dropping the lifted clothes so that the clothes can be washed by means of friction and impact. The drum washing machine is capable of heating wash water and spraying the heated wash water into a tub and a drum of the washing machine in a phase of high-temperature and high-pressure steam, thereby rapidly soaking clothes in the wash water, improving sterilizing and washing efficiencies of the drum washing machine, and saving wash water and electric energy.

This application is a Divisional of co-pending application Ser. No.10/753,496 filed on Jan. 9, 2004, and for which priority is claimedunder 35 U.S.C. § 120, and this application claims priority ofApplication No. 2003-20204 filed in Korea on Mar. 31, 2003 under 35U.S.C. § 119; the entire contents of all are hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a drum washing machine which is capableof lifting clothes to a predetermined height and then dropping thelifted clothes so that the clothes can be washed by means of frictionand impact, and more particularly to a steam jet drum washing machinewhich is capable of heating wash water and spraying the heated washwater into a tub and a drum of the washing machine in a phase ofhigh-temperature and high-pressure steam, whereby sterilizing andwashing efficiencies of the drum washing machine are improved.

2. Description of the Related Art

A drum washing machine is a kind of washer which is capable of washingclothes by friction between a drum rotated by a motor and the clothesput in the drum while a detergent and wash water are supplied in ahorizontally mounted tub and the drum, which is disposed in the tub.With the drum washing machine, the clothes are neither damaged nortangled with one another. Furthermore, the drum washing machine washesclothes by striking and rubbing the clothes, whereby washing efficiencyis improved.

FIG. 1 is a perspective view of a conventional drum washing machine, andFIG. 2 is a side view, in cross section, of the conventional drumwashing machine.

As shown in FIGS. 1 and 2, the conventional drum washing machinecomprises: a casing 2 forming the exterior of the drum washing machine;a tub 6 disposed in the casing 2 in such a manner that the tub 6 issuspended by means of springs 4 and simultaneously supported by means ofdamper assemblies 5; a drum 8 rotatably mounted in the tub 6, in whichclothes are put and into which wash water is supplied; a plurality ofvanes 8 a provided on the inner circumference of the drum 8 for liftingthe clothes in the drum 8 as the drum 8 is rotated, the vanes 8 a beinglongitudinally extended parallel to the axis of rotation of the drum 8and inwardly protruded to a predetermined height while the vanes 8 a areuniformly spaced apart from each other; and a motor 10 connected to thedrum 8 in the rear of the tub 6 for rotating the drum 8.

The drum washing machine further comprises: a water-supply valveassembly 12 mounted above the tub 6 for supplying wash water into thetub 6 and the drum 8; a detergent box assembly 14 also mounted above thetub 6 for supplying a detergent into the tub 6 and the drum 8; and adrainage pump assembly 16 mounted below the tub 6 for draining the washwater from the tub 6 and the drum 8.

The drum 8 is provided at the inner circumference thereof with aplurality of through-holes 8 h, through which the wash water flowsbetween the drum 8 and the tub 6. When the drum 8 is rotated to dewaterthe clothes, the wash water contained in the clothes is separated fromthe clothes by means of the centrifugal force of the drum 8. At thistime, the wash water separated from the clothes is discharged throughthe through-holes 8 h. The water-supply valve assembly 12 includes awater-supply valve (not shown) so that the water-supply valve assembly12 supplies wash water into the tub 6 and the drum 8 when thewater-supply valve is opened. Similarly, the drainage pump assembly 16includes a drainage pump (not shown) so that the drainage pump assembly16 discharges the wash water from the tub 6 and the drum 8 when thedrainage pump is operated.

To the lower part of the tub 6 is mounted a heater 20 for heating washwater in the tub 6 to a high temperature, by which the washingefficiency is improved. Specifically, the tub 6 includes a heatermounting part 6 a formed at the lower part thereof. The heater mountingpart 6 a of the tub 6 is downwardly extended from the tub 6 so that theheater 20 is mounted in the heater mounting part 6 a. The heater 20 isslidably inserted into the heater mounting part 6 a of the tub 6 fromthe front part thereof, and then securely fixed to the heater mountingpart 6 a of the tub 6.

The operation of the conventional drum washing machine with theabove-stated construction will now be described.

When a washing process is performed while clothes are put in the drum 8,the water-supply valve is opened so that a proper amount of wash wateris supplied into the tub 6 and the drum 8 depending upon the amount ofthe clothes. The wash water passes through the water-supply valveassembly 12, and then passes through the detergent box assembly 14. Thewash water having passed through the detergent box assembly 14 issupplied into the tub 6 together with a detergent.

When the drum 8 is rotated by operation of the motor 10, the clothes arelifted to a predetermined height by the vanes 8 a and then dropped fromthe vanes 8 a so that the clothes can be washed by means of friction andimpact. At this time, the heater 20 may be operated to heat the washwater in the tub 6 so that the washing efficiency is improved.

After the washing process is finished, the drainage pump is operated sothat the wash water is discharged. Subsequently, the motor 10 is rotatedat a high speed, and thus the drum 8 is also rotated at a high speed.When the drum 8 is rotated, the wash water contained in the clothes isseparated from the clothes by means of the centrifugal force of the drum8. At this time, the wash water separated from the clothes is dischargedthrough the through-holes 8 h. In this way, an intermittent dewateringprocess is performed. Thereafter, the water-supply valve is opened againso that wash water is supplied into the tub 6 and the drum 8. At thesame time, the drum 8 is rotated so that a rinsing process is performed.

The aforementioned rinsing and intermittent dewatering processes arealternately and repeatedly carried out, and finally a dewatering processis performed. In this way, a cleaning process comprising washing,rinsing, and dewatering processes is completed.

In the conventional drum washing machine, however, the wash water issupplied into the tub 6 from the upper part thereof together with thedetergent via the water-supply valve assembly 12 and the detergent boxassembly 14, and the wash water supplied into the tub 6 is heated by theheater 20 mounted to the lower part of the tub 6. As can be easilyunderstood from the above description, the wash water initially suppliedinto the tub is cold. Consequently, the wash water is slowly absorbed bythe clothes.

The conventional drum washing machine includes the heater mounting part6 a of the tub 6, which is provided so that the heater 20 is mounted inthe tub 6. The heater mounting part 6 a is formed at the lower part ofthe tub 6 in such a manner that the heater mounting part 6 a isdownwardly extended from the tub 6. Consequently, it is required toprovide an additional space necessary for forming the heater mountingpart 6 a in the tub 6, which complicates construction of the drumwashing machine.

The wash water supplied in the tub 6 is heated by the heater 20. Sincethe heater 20 is mounted in the heater mounting part 6 a of the tub 6,the wash water is also filled in the heater mounting part 6 a of the tub6, and thus the wash water filled in the heater mounting part 6 a of thetub 6 is also heated. However, the wash water filled in the heatermounting part 6 a of the tub 6 is not used to wash the clothes.Consequently, wash water and electric energy are uselessly wasted. Inaddition, the detergent is left with the wash water in the heatermounting part 6 a of the tub 6, by which the washing efficiency of thedrum washing machine is decreased.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the aboveproblems, and it is an object of the present invention to provide asteam jet drum washing machine which is capable of heating wash waterand spraying the heated wash water into a tub and a drum of the washingmachine in a phase of high-temperature and high-pressure steam, therebyrapidly soaking clothes in the wash water, reducing waste of the washwater and electric energy, and improving sterilizing and washingefficiencies of the drum washing machine.

In accordance with the present invention, the above and other objectscan be accomplished by the provision of a steam jet drum washing machinecomprising: a tub disposed in a casing and adapted so that wash water issupplied into the tub; a drum rotatably mounted in the tub and adaptedso that clothes are put in the drum and the wash water is supplied intothe drum; a water-supply unit disposed at one side of the tub forsupplying the wash water into the tub and the drum; and a steamgenerator connected to the water-supply unit for heating the wash waterto obtain high-temperature and high-pressure steam, and supplying thehigh-temperature and high-pressure steam into the tub and the drum.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a perspective view of a conventional drum washing machine;

FIG. 2 is a side view, in cross section, of the conventional drumwashing machine;

FIG. 3 is a perspective view of a steam jet drum washing machineaccording to a first preferred embodiment of the present invention;

FIG. 4 is a side view, in cross section, of the steam jet drum washingmachine according to the first preferred embodiment of the presentinvention;

FIG. 5 is a perspective view, partially cutaway, of a steam generator ofthe present invention; and

FIG. 6 is a perspective view of a steam jet drum washing machineaccording to a second preferred embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, preferred embodiments of the present invention will be described indetail with reference to the accompanying drawings. In the drawings, thesame or similar elements are denoted by the same reference numerals eventhough they are depicted in different drawings.

FIG. 3 is a perspective view of a steam jet drum washing machineaccording to a first preferred embodiment of the present invention, FIG.4 is a side view, in cross section, of the steam jet drum washingmachine according to the first preferred embodiment of the presentinvention, and FIG. 5 is a perspective view, partially cutaway, of asteam generator of the present invention.

As shown in FIGS. 3 and 4, the steam jet drum washing machine accordingto the first preferred embodiment of the present invention comprises: acasing 52 forming the exterior of the drum washing machine; a tub 56disposed in the casing 52 in such a manner that the tub 56 is suspendedby means of springs 54 and elastically supported by means of damperassemblies 55; a drum 58 rotatably mounted in the tub 56, in whichclothes are put and into which wash water is supplied; a plurality ofvanes 58 a provided on the inner circumference of the drum 58 forlifting the clothes in the drum 58 as the drum 58 is rotated, the vanes58 a being longitudinally extended parallel to the axis of rotation ofthe drum 58 and inwardly protruded to a predetermined height while thevanes 58 a are uniformly spaced apart from each other; a motor 60connected to the drum 58 in the rear of the tub 56 for rotating the drum58; and a steam generator 70 disposed above the tub 56 for heating thewash water to obtain high-temperature and high-pressure steam, which issupplied to the tub 56 and the drum 58.

The drum washing machine further comprises: a water-supply unit 62mounted above the tub 56 for supplying wash water into the tub 56 andthe drum 58; and a drainage pump assembly 66 mounted below the tub 56for draining the wash water from the tub 56 and the drum 58. The steamgenerator 70 is connected to the water-supply unit 62.

The water-supply unit 62 comprises: a water-supply valve assembly 62 amounted to the rear of the casing 52 for supplying wash water; adetergent box assembly 62 b mounted between the water-supply valveassembly 62 a and the tub 56 for storing a detergent; a water-supplytube 62 c connected between the water-supply valve assembly 62 a and thesteam generator 70; an auxiliary water-supply tube 62 c′ connectedbetween the water-supply valve assembly 62 a and the detergent boxassembly 62 b; and a steam tube 62 d having one end connected to thesteam generator 70 and the other end 62 d′ disposed in the tub 56 andthe drum 58 for supplying the steam into the tub 56 and the drum 58.

Alternatively, the water-supply unit 62 may comprise the water-supplyvalve assembly 62 a, the water-supply tube 62 c, and the steam tube 62 dso that the wash water is supplied into the tub 56 and the drum 58 viaonly the steam generator 70.

The drum 58 is provided at the inner circumference thereof with aplurality of through-holes 58 h, through which the wash water flowsbetween the drum 58 and the tub 56. When the drum 58 is rotated todewater the clothes, the wash water contained in the clothes isseparated from the clothes by means of the centrifugal force of the drum58. At this time, the wash water separated from the clothes isdischarged through the through-holes 58 h. The water-supply valveassembly 62 includes a water-supply valve (not shown) so that thewater-supply valve assembly 62 supplies wash water into the tub 56 andthe drum 58 when the water-supply valve is opened. Similarly, thedrainage pump assembly 66 includes a drainage pump (not shown) so thatthe drainage pump assembly 66 discharges the wash water from the tub 56and the drum 58 when the drainage pump is operated.

The water-supply tube 62 c is connected between the water-supply valveassembly 62 a and the steam generator 70 so that the wash water issupplied into the steam generator 70. The auxiliary water-supply tube 62c′ is connected between the water-supply valve assembly 62 a and thedetergent box assembly 62 b so that the wash water is supplied into thedetergent box assembly 62 b.

The end 62 d′ of the steam tube 62 d is formed in the shape of a nozzleso that steam is sprayed at a high speed from the end 62 d′. The end 62d′ of the steam tube 62 d penetrates through the upper end of a gasket57, which is made of rubber, for preventing leakage of water between thetub 56 and the casing 52. Consequently, the steam guided along the steamtube 62 d is downwardly sprayed through the end 62 d′ of the steam tube62 d into the tub 56 and the drum 58.

The water-supply tube 62 c and the steam tube 62 d are relatively shortby the provision of the steam generator 70. The steam generator 70 isdisposed above the tub 56 between the tub 56 and the casing 52 so thatrepair and inspection of the stem generator 70 can be easily andconveniently conducted.

As shown in FIG. 5, the steam generator 70 comprises: an airtightpressure container 72 connected at the top end thereof to thewater-supply tube 62 c and the steam tube 62 d and having an inner spacefor storing wash water defined therein; a heater 74 mounted in thepressure container 72 for heating the wash water stored in the pressurecontainer 72; an inlet valve 76 a disposed between the water-supply tube62 c and the pressure container 72 for supplying the wash water into thepressure container 72; and an outlet valve 76 b disposed between thesteam tube 62 d and the pressure container 72 for supplying steam intothe steam tube 62 d.

The pressure container 72 comprises an upper container part 72 a formingthe upper part of the pressure container 72, and a lower container part72 b forming the lower part of the pressure container 72. The uppercontainer part 72 a and the lower container part 72 b are preferablyattached to each other by means of bolts (not shown).

The inlet valve 76 a and the outlet valve 76 b are pressure valves thatcan be opened or closed depending upon the pressure inside the pressurecontainer 72. The inlet valve 76 a may be controlled either electricallyor mechanically so that the inlet valve 76 a is opened when the pressureinside the pressure container 72 is below a predetermined pressure.Similarly, the outlet valve 76 b may be controlled either electricallyor mechanically so that the inlet valve 76 a is opened when the pressureinside the pressure container 72 is over a predetermined pressure.

The steam generator 70 further comprises: a water level sensor 77disposed at the upper part of the pressure container 72 for sensing theamount of the wash water stored in the pressure container 72 to controlthe operation of the inlet valve 76 a and the outlet valve 76 b; and atemperature sensor 78 disposed at the lower part of the pressurecontainer 72 for sensing the temperature inside the pressure container72 to control the operation of the heater 74 on the basis of thetemperature inside the pressure container 72.

The water level sensor 77 senses the level of the wash water on thebasis of the movement of a float on the wash water. Alternatively, thewater level sensor 77 may sense the level of the wash water on the basisof the change in inside pressure of the pressure container 72 when thewash water is supplied into the pressure container 72.

The heater 74 is horizontally disposed in the lower container part 72 bso that heater 74 can be submerged under the wash water even when thewash water is supplied into the pressure container 72 to the minimumwater level.

The heater 74 is preferably formed in the shape of a curved pipe so thatthe heating surface area is increased. The heater 74 may be overheatedwhile the heater 74 is energized. Consequently, there is preferablyprovided a safety unit for preventing overheating of the heater 74.

The safety unit comprises: an automatic pressure switch 79 a disposed bythe side of the water level sensor 77 for cutting off the supply ofelectric current to the heater 74 to primarily stop the operation of theheater 74 when the pressure inside the pressure container 72 is over apredetermined pressure; and an automatic temperature switch 79 b, suchas a thermostat, disposed by the side of the temperature sensor 78 forcutting off the supply of electric current to the heater 74 tosecondarily stop the operation of the heater 74 when the temperatureinside the pressure container 72 is over a predetermined temperature.

Additional automatic temperature switches 79 b may be disposed forpreventing overheating of the heater 74 when the automatic pressureswitch 79 a is not normally operated or when the pressure container 72leaks.

The steam generator 70 further comprises a thermal insulator 75, such asStyrofoam, for shielding the pressure container 72 to prevent thermalenergy generated in the pressure container 72 from leaking out of thepressure container 72 when the heater 74 is operated.

In the steam generator 70 with the above-stated construction, theoperation of the heater 74, the inlet valve 76 a, and the outlet valve76 b are controlled by a controller (not shown) for controlling theoperation of the drum washing machine.

FIG. 6 is a perspective view of a steam jet drum washing machineaccording to a second preferred embodiment of the present invention.

The steam jet drum washing machine according to the second preferredembodiment of the present invention is identical to the steam jet drumwashing machine according to the first preferred embodiment of thepresent invention except that the steam generator 70 is disposed belowthe tub 56 between the tub 56 and the casing 52, as shown in FIG. 6.

Consequently, the water-supply tube 63 c connected between the steamgenerator 70 and the water-supply valve assembly (not shown) is disposedbetween one side of the tub 56 and the casing 52. Similarly, the steamtube 63 d connected between the steam generator 70 and the tub 56 isdisposed between one side of the tub 56 and the casing 52.

When the steam generator 70 is disposed below the tub 56 as describedabove, an empty space defined below the tub 56 between the tub 56 andthe casing 52 may be used as the installation space for the steamgenerator 70. Consequently, the total size of the drum washing machineis not increased even though the steam generator 70 is mounted in thedrum washing machine.

The operation of the steam jet drum washing machine with theabove-stated construction according to the present invention will now bedescribed.

When a washing process is performed while clothes are put in the drum58, the water-supply valve is opened so that a proper amount of washwater is supplied into the tub 56 and the drum 58 depending upon theamount of the clothes. The wash water passes through the auxiliarywater-supply tube 62 c′, and then passes through the detergent boxassembly 62 b. The wash water having passed through the detergent boxassembly 62 b is supplied into the tub 56 together with a detergent.

When the wash water is to be sprayed in a phase of steam according to auser's selection, the wash water passes through the water-supply tube 62c, and is then supplied into the steam generator 70 where the wash wateris heated to obtain high-temperature and high-pressure steam. Thehigh-temperature and high-pressure steam generated in the steamgenerator 70 is sprayed into the tub 56 and the drum 58 via the steamtube 62 d.

Specifically, when the water-supply valve is opened so that the washwater is supplied via the water-supply tube 62 c, the wash water issupplied into the pressure container 72 while the inlet valve 76 a andthe outlet valve 76 b are opened. As the wash water is supplied into thepressure container 72, the water level sensor 77 senses the level of thewash water in the pressure container 72.

At this time, the inlet valve 76 a is opened so that the wash water issupplied into the pressure container 72, and the outlet valve 76 b isopened so that air is discharged from the pressure container 72.

When a proper amount of the wash water is supplied into the pressurecontainer 72, the inlet valve 76 a and the outlet valve 76 b are closed,and simultaneously the heater 74 is operated to heat the wash water sothat high-temperature and high-pressure steam is generated.

Since the heater 74 is operated in the airtight space in the pressurecontainer 72, higher-temperature and higher-pressure steam may begenerated as the heater 74 is operated for a longer time.

At this time, the temperature sensor 78 senses the temperature of theinterior of the pressure container 72, and the operation of the heater74 is controlled on the basis of the sensed temperature so that theheater 74 is not overheated.

When the temperature sensor 78 is out of order or abnormally operated,the automatic pressure switch 79 a and the automatic temperature switch79 b are operated to cut off the supply of electric current to theheater 74 so that overheating of the heater 74 is prevented.

When the heater 74 is operated, the wash water supplied into theairtight pressure container 72 is heated to generate high-temperatureand high-pressure steam. When the temperature sensor 78 senses that thetemperature of the interior of the pressure container 72 is over apredetermined pressure, the outlet valve 76 b is opened so that thesteam passes through the steam tube 62 d and is then sprayed into thetub 56 and the drum 58.

At this time, the steam is sprayed into the tub 56 and the drum 58through the end 62 d′ of the steam tube, which is formed in the shape ofa nozzle. As a result, the clothes are rapidly soaked.

When a proper amount of the wash water is supplied into the tub 56 andthe drum 58, the water-supply valve is closed, and the motor 60 isoperated. When the drum 58 is rotated by operation of the motor 60, theclothes are lifted to a predetermined height by the vanes 58 a and thendropped from the vanes 58 a. In this way, a washing process isperformed.

After the washing process is finished, the drainage pump is operated sothat the wash water is discharged. Subsequently, the motor 60 is rotatedat a high speed, and thus the drum 58 is also rotated at a high speed.When the drum 58 is rotated, the wash water contained in the clothes isseparated from the clothes by means of the centrifugal force of the drum58. In this way, an intermittent dewatering process is performed. Thewater-supply valve is opened again so that wash water is supplied intothe tub 56 and the drum 58 to a predetermined level via the auxiliarywater-supply tube 62 c′. Thereafter, the drum 58 is rotated so that arinsing process is performed.

The aforementioned rinsing and intermittent dewatering processes arealternately and repeatedly carried out, and finally a dewatering processis performed. In this way, a process for cleaning the clothes iscompleted.

It should be noted that the wash water may be supplied into the steamgenerator 70 where the wash water is heated to obtain high-temperatureand high-pressure steam, and the high-temperature and high-pressuresteam may be sprayed into the tub 56 and the drum 58 even when theclothes are washed or rinsed as well as when the wash water is initiallysupplied into the tub 56 and the drum 58, in order to improvesterilizing and washing efficiencies of the drum washing machine.

As apparent from the above description, the present invention provides asteam jet drum washing machine characterized in that wash water issupplied into a steam generator where the wash water is heated to obtainhigh-temperature and high-pressure steam, and the steam is sprayed intoa tub and a drum of the drum washing machine, thereby rapidly soakingclothes in the wash water when the wash water is initially supplied intothe tub and the drum, saving wash water and electric energy.Furthermore, the wash water is supplied in a phase of high-temperatureand high-pressure steam when clothes are washed and rinsed, wherebysterilizing and washing efficiencies of the drum washing machine areimproved.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

1. A washing method for a steam jet washing machine comprising: a watersupplying step for supplying wash water into a tub; a steam supplyingstep for supplying steam into a drum by operating a steam generator; anda drum driving step for driving the drum.
 2. The washing method for thesteam jet washing machine of claim 1, wherein the steam supplying stepfor supplying steam into a drum by operating a steam generator and thedrum driving step for driving the drum are performed after completingthe water supplying step for supplying wash water into a tub.
 3. Thewashing method for the steam jet washing machine of claim 1, wherein thesteam supplying step for supplying steam into a drum by operating asteam generator and the drum driving step for driving the drum areperformed simultaneously.
 4. The washing method for the steam jetwashing machine of claim 1, wherein the steam supplying step comprises:a water supplying step for supplying wash water into the steamgenerator; a heater driving step for driving a heater of the steamgenerator to generate steam; and a steam spraying step for sprayingsteam into the drum.
 5. A washing method for a steam jet washing machinecomprising a tub disposed within a cabinet and adapted so that washwater is supplied into the tub; a drum rotatably mounted in the tub andadapted so that wash water is supplied into the tub; a water-supply unitdisposed at one side of the tub for supplying the wash water into thetub and the drum; and a steam generator connected to the water-supplyunit for heating the wash water to obtain high-temperature andhigh-pressure, and supplying the high-temperature and high pressuresteam into the tub and the drum, comprising: a water supplying step forsupplying wash water into the tub; a steam supplying step for supplyingsteam into the drum by operating the steam generator; and a drum drivingstep for driving the drum.
 6. The washing method for a steam jet washingmachine of claim 5, wherein the steam supplying step for supplying steaminto the drum by operating the steam generator and the drum driving stepfor driving the drum are performed after completing the water supplyingstep for supplying wash water into the tub.
 7. The washing method for asteam jet washing machine of claim 5, wherein the steam supplying stepfor supplying steam into the drum by operating the steam generator andthe drum driving step for driving the drum are performed simultaneously.8. The washing method for a steam jet washing machine of claim 5,wherein the steam supplying step for supplying steam into the drum byoperating the steam generator comprises: a water supplying step forsupplying wash water into the steam generator; a heater driving step fordriving a heater of the steam generator to generate steam; and a steamspraying step for spraying steam into the drum.